Bisazo photoconductor for electrophotography

Abstract

A photoconductor for electrophotography includes an electroconductive substrate and a photosensitive layer formed on the substrate. The photosensitive layer includes a novel bisazo compound as a charge generating substance therein. One type of bisazo compound is represented by general formula: <IMAGE> wherein, A stands for a coupler residue.

What is claimed is: 
     
       1. A photoconductor for electrophotography, comprising: an electroconductive substrate; and   a photosensitive layer formed on said electroconductive substrate and containing a charge generating substance and a change transporting substance in a binder, said change generating substance being at least one bisazo compound having general formula (I): ##STR93##  wherein A is a coupler residue selected from the group consisting of formulae (V) to (XI): ##STR94##  wherein Z stands for a residual group which condenses with a benzene ring to form an aromatic polycycle or a heterocycle, X 1  is selected from the group consisting of OR 1  and NR 2  R 3 , each of R 1 , R 2  and R 3  is selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 2  and X 5  is selected from the group consisting of an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 3  and X 6  is selected from the group consisting of a hydrogen atom, a cyano group, a carbamoyl group, a carboxyl group, an ester group and an acyl group, each of X 4  and X 11  is selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 7  and X 8  is selected from the group consisting of a hydrogen atom, a halogen atom, a nitro group, an alkyl group and an alkoxy group, the last two of which groups may be substituted, X 9  is selected from the group consisting of an alkyl group, an aryl group, a carboxyl group and an ester group, which groups may be substituted, X 10  is selected from the group consisting of an aryl group and a heterocyclic group, which groups may be substituted, and Y is a residual group which forms an aromatic ring or a heterocycle.   
     
     
       2. The photoconductor as claimed in claim 1, wherein said photosensitive layer comprises a layer including a dispersion of said charge generating substance selected from bisazo compounds having general formula (I) and said charge transporting substance. 
     
     
       3. The photoconductor as claimed in claim 1, wherein said photosensitive layer has laminated layers, one of which is a charge transporting layer mainly composed of said charge transporting substance and another of which is a charge generating layer containing said charge generating substance selected from bisazo compounds having general formula (I). 
     
     
       4. A photoconductor for electrophotography, comprising: an electroconductive substrate; and   a photosensitive layer formed on said electroconductive substrate and containing a charge generating substance and a charge transporting substance in a binder, said charge generating substance being at least one bisazo compound having general formula (II): ##STR95##  wherein A is a coupler residue selected from the group consisting of formulae (V) to (XI): ##STR96##  wherein Z is a residual group which condenses with a benzene ring to form an aromatic polycycle or a heterocycle, X 1  is selected from the group consisting of OR 1  and NR 2  R 3 , each of R 1 , R 2  and R 3  is selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 2  and X 5  is selected from the group consisting of an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 3  and X 6  is selected from the group consisting of a hydrogen atom, a cyano group, a carbamoyl group, a carboxyl group, an ester group and an acyl group, each of X 4  and X 11  is selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 7  and X 8  is selected from the group consisting of a hydrogen atom, a halogen atom, a nitro group, an alkyl group and an alkoxy group, the last two of which groups may be substituted, X 9  is selected from the group consisting of an alkyl group, an aryl group, a carboxyl group and an ester group, which groups may be substituted, X 10  is selected from the group consisting of an aryl group and a heterocyclic group, which groups may be substituted, and Y is a residual group which forms an aromatic ring or a heterocycle.   
     
     
       5. The photoconductor as claimed in claim 1, wherein said photosensitive layer comprises a layer including a dispersion of said charge generating substance selected from bisazo compounds having general formula (II) and said charge transporting substance. 
     
     
       6. The photoconductive as claimed in claim 1, wherein said photosensitive layer has laminated layers, one of which is a charge transporting layer mainly composed of said charge transporting substance and another of which is a charge generating layer containing said charge generating substance selected from bisazo compounds having general formula (II). 
     
     
       7. A photoconductor for electrophotography, comprising: an electroconductive substrate; and   a photosensitive layer formed on said electroconductive substrate and containing a charge generating substance and a charge transporting substance in a binder, said charge generating substance being at least one bisazo compound having general formula (III): ##STR97##  wherein A is a coupler residue selected from the group consisting of formulae (V) to (XI): ##STR98##  wherein Z stands for a residual group which condenses with a benzene ring to form an aromatic polycycle or a heterocycle, X 1  is selected from the group consisting of OR 1  and NR 2  R 3  each of R 1 , R 2  and R 3  is selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 2  and X 5  is selected from the group consisting of an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 3  and X 6  is selected from the group consisting of a hydrogen atom, a cyano group, a carbamoyl group, a carboxyl group, an ester group and an acyl group, each of X 4  and X 11  is selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 7  and X 8  is selected from the group consisting of a hydrogen atom, a halogen atom, a nitro group, an alkyl group and an alkoxy group, the last two of which groups may be substituted, X 9  is selected from the group consisting of an alkyl group, an aryl group, a carboxyl group and an ester group, which groups may be substituted, X 10  is selected from the group consisting of an aryl group and a heterocyclic group, which groups may be substituted, and Y is a residual group which forms an aromatic ring or a heterocycle.   
     
     
       8. The photoconductive as claimed in claim 1, wherein said photosensitive layer comprises a layer including a dispersion of said charge generating substance selected from bisazo compounds represented by the general formula (III) and said charge transporting substance. 
     
     
       9. The photoconductor as claimed in claim 1, wherein said photosensitive layer has laminated layers, one of which is a charge transporting layer mainly composed of said charge transporting substance and another of which is a charge generating layer containing said charge generating substance selected from bisazo compounds having general formula (III). 
     
     
       10. A photoconductor for electrophotography, comprising: an electroconductive substrate; and   a photosensitive layer formed on said substrate and containing a charge generating substance and a charge transporting substance in a binder, said charge generating substance being at least one bisazo compound having general formula (IV): ##STR99##  wherein R 4  is selected from the group consisting of a hydrogen atom, an alkyl group and an aryl group which may be substituted, n stands for an integer of 1 to 3, and A is a coupler residue selected from the group consisting of formulae (V) to (XI): ##STR100##  wherein Z stands for a residual group which condenses with a benzene ring to form an aromatic polycycle or a heterocycle, X 1  is selected from the group consisting of OR 1  and NR 2  R 3 , each of R 1 , R 2  and R 3  is selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 2  and X 5  is selected from the group consisting of an alkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 3  and X 6  is selected from the group consisting of a hydrogen atom, a cyano group, a carbamoyl group, a carboxyl group, an ester group and an acyl group, each of X 4  and X 11  is selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group and a heterocyclic group, which groups may be substituted, each of X 7  and X 8  is selected from the group consisting of a hydrogen atom, a halogen atom, a nitro group, an alkyl group and an alkoxy group, the last two of which groups may be substituted, X 9  is selected from the group consisting of an alkyl group, an aryl group, a carboxyl group and an ester group, which groups may be substituted, X 10  is selected from the group consisting of an aryl group and a heterocyclic group, which groups may be substituted and Y is a residual group which forms an aromatic ring or a heterocycle.   
     
     
       11. The photoconductor as claimed in claim 1, wherein said photosensitive layer comprises a layer including a dispersion of said charge generating substance selected from bisazo compounds having general formula (IV) and said charge transporting substance. 
     
     
       12. The photoconductive as claimed in claim 1, wherein said photosensitive layer has laminated layers, one of which is a charge transporting layer mainly composed of said charge transporting substance and another of which is a charge generating layer containing said charge generating substance selected from bisazo compounds having general formula (IV).